Holistic Site Development: With Floodplain, Stream Habitat and Wetland Mitigation

Indian Creek, located north of Aurora in Kane County, Illinois, is an urbanizing watershed with a history of flooding problems, particularly along the channelized middle section. The proposal to develop approximately 140 acres in the upper reaches of the watershed highlighted the opportunity to prepare a holistic site development plan mitigating for historic degradation of the stream riparian corridor. Proposed development plans for the 140 acre parcel include the construction of a retail outlet mall, 80 acres of wetland, stream and prairie complex with 300 acre-feet of flood storage. This paper describes the various components of the development plan broken down into four primary categories: floodplain, fluvial geomorphology, ecological assessment and wetland mitigation. The hydrologic and hydraulic conditions along the upper nine square miles of Indian Creek were evaluated utilizing HEC-1 and the dynamic FEQ computer program. The fluvial geomorphic, hydrologic and stream habitat considerations involved in the conversion of 3100 feet of channelized agricultural ditch into 4200 feet of re-meandered and naturalized stream channel are presented. The proposed stream design incorporates channel re-meandering, riffle and pool structures, in-stream cover, substrate diversity and various forms of streambank stabilization. Stream benthic macroinvertebrate population assessments were performed to determine the base line stream quality. The wetland mitigation design